1. Field of the Invention
This invention generally relates to apparatus for harvesting above-ground vegetable crops, such as tomatoes. More particularly, the present invention concerns harvesters of the type which include a shaking mechanism for removing fruit from the vine and means for collecting said fruit.
2. Description of the Prior Art
Direct-loading harvesters have been known in the art for many years and have recently enjoyed wide-spread use in the harvesting of tomatoes. Typically, such harvesters are arranged to harvest tomato plants grown in rows, to elevate the harvested plants to shaker conveyors for separating tomatoes from their vines, to carry the tomatoes from the shaker conveyors to sorter conveyors where undesired tomatoes and trash are removed, and finally to elevate the remaining tomatoes from the harvester to an attendant truck or trailer for delivery to processing plants.
The shaker conveyor on a conventional harvester is mounted on the main frame of the harvester and comprises a plurality of endless parallel conveyor chains that are transversely spaced to allow the tomatoes to drop therebetween to an underlying collection conveyor. The shaking action which causes the tomatoes to separate from the vines is imparted by oscillating a subframe on which the shaker conveyor is mounted either transversely or longitudinally with respect to the main frame. The conveyor chains are provided with outwardly extending fingers which engage the tomato vines and aid in transmitting the shaking force to the vines. Such shaker conveyors are disclosed in U.S. Pat. No. 3,071,196 to Scheidenhelm and U.S. Pat. No. 4,174,755 to Siri.
Shaker conveyors of the type described above have proved to have a serious maintenance problem. The shaking action places severe strain on the chains of the shaker conveyor leading to frequent breakage of the links and consequent downtime of the harvester. It is therefore desirable that a harvester be provided with a shaking mechanism which will operate for long periods of time without requiring maintenance. Specifically, it is desirable to have a shaking mechanism which does not impart severe stress to the shaker conveyor as is the case in the prior art.